hc samplings ,procedure

8/12/2019 HC Samplings ,Procedure

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Prepared by:

Shailesh Ghediya


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Sampling is done in order to analyze the parametersrequired for control of the process.

Sampling can be classified into two types:

Open sampling

Close sampling


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In open sampling the sample comes in contact with

atmosphere.

For the streams whose temperature is less than auto ignitiontemperature, which is free of H2S or any toxic gas which is

not high flammable open sampling is done.

In short, open sampling is advisable for the streams whichdo not lead to fire, H2S inhalation and danger to life.


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Open sampling set up will have process coil immersed in awater bath (cooler).

Inlet of the Process coil setup will be from process line andthe outlet line will be either circulated or routed to slop tankto get fresh stream of the sample and not the holdup material

which is undesirable. Streams like VGO feed, VGO product and Diesel can be taken

in open sampling setup.

Similarly steam and steam generator blow down /condensatesample can be taken by open sampling set up.


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Closed sampling is done in sample bombs at approvedsample stations meant for closed sampling.

Recycle gas, Sour water, Naphtha, Propylene have to be takenas close sample.

Recycle gas can be taken as bladder sample only as a special

requirement and required safety precautions and proceduresto be followed while pursuing the activity


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Hazards Precautions

Hot HC material coming duringsampling.

Accidental touching of samplebooth coil (In case of openboot)

Splash of hot liquids

Hydrogen can lead toFire/explosion

Always open water in samplecooler before opening anyprocess valves.

Heat resistance gloves to beuse along with mandatory PPEs

Operate sampling stationvalves slowly.

Wear splashguard helmetduring.

Keep sure that sample bombsare tested at regular intervals


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Ensure Fire Water Hose is ready for use. Ensure valves A, B, C, D & E are closed.

Open valve E keeping D closed, which fills sample station cooler with water

And let water overflow through the overflow line.

Slowly open valve B.

Open the valve A and allow the hydro carbon to flow.

Keep circulation on for 4-5 minutes. Close the valve B Slowly.

Slowly open valve C, Keeping the glass bottle for sampling in such a way thatit is away from body of the person taking the sample.

Adjust the flow rate of sampling stream such that it gets cooled so thatbottle can be held comfortably. With gloves on.

Flush the sample bottle and take sample.

Close the valve A ,Close the valve C &Close cooling water supply valve E.

Open valve D to drain the sample cooler water.

Shift the sample bottle to sample station holding it comfortably and securely.


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Inform panel officer for sampling with specific location of samplepoint with sample name.

Ensure that system is de pressurized & all valves are closed. Confirmin the PG. It should be 0.1-0.2kg/cm2g

Insert the sample bomb in the bottom quick release coupling-1(QC-

2) connect the SS hose to the bomb top quick release coupling-2(QC-2)

Open bomb valve V5,V6 & than V2, V3

Open main supply valve V2 than return valve V7.

Watch the PG for pressure in the manifold. It should match withprocess pressure.

Let the sample flow through the bomb for 5-10 minute to flush thebomb.

Close the bomb outlet valve V6.


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After 1-2 minute close the bomb inlet valve V5 than close valve V2 &V3

Close supply valve V1 & than return valve V7.

Open valve V4 & V8 to depressurize manifold, Confirm de-pressurization with pressure gauge .It should be 0.1-0.2 kg /cm2

Close vent valve and release SS hose at the top of bomb thandisconnect bomb and Connect the SS hose at bottom QC-2


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An area field executive from DTA aromatics unit received burninjury while collecting sample

The temporary hose connection which was fitted between processline and sampler got detached from joint

This result into splashing hot condensate over his chest area causing

8-10% burn injury on chest and right lower part of cheek. Injured person was given medical treatment at our DA OH &FWC and

total lost work days were 13 days


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Over pressurization. Synchronization of valve A &C.

The wire braided rubber hose which is design for LP steamservice (working pressure 10 kg/cm2 and temp 150 deg C.)found in use for MP steam.

The hose was connected with single C clamp instead two.

Temporary hose was supported using wire.

There is no formal system exist for doing necessary checkson integrity of temporary hose connection using check list.

There was no formal record of HSE review /Risk assessmentavailable with operation for affecting the temporary change

There was no identification tag affixed on the hose.


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Practice consistent with procedure Absent of shortcuts

Risk sensitivity


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hc samplings ,procedure

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